Antilocking mechanisms are known in which a control valve is disposed in a main braking fluid line leading from the main or master cylinder to the wheel brake cylinder, which valve has two positions. In one of those positions there is free passage of the braking medium in both directions, and in the second position only the return flow from the wheel to the master brake cylinder is possible. In the event of locking, the brake medium is pumped by means of a pump in the direction toward the master brake cylinder for the purpose of decreasing pressure in the wheel cylinder. The path followed by the brake medium in that event is different depending on the type of construction. In some constructions, the same path that has been taken by the brake medium from the master cylinder to the wheel cylinder is followed, and in others it can be a by-pass line of the control valve which has two check valves opening in the direction toward the master cylinder with the pump between them, wherein this path, in addition, may have a blow-off or surge tank in front of the first check valve and therefore must be closed by still another valve with respect to the main brake line, etc.
All such systems have the one disadvantage in common that for every regulation of a wheel a separate pump with a corresponding drive must be available.